Hilary of Poitiers

Or; By the lilies are to be understood the eminences of the heavenly Angels, to whom a surpassing radiance of whiteness is communicated by God. They toil not, neither do they spin, because the angelic powers received in the very first allotment of their existence such a nature, that as they were made so they should ever continue to be; and when in the resurrection men shall be like unto Angels, He would have them look for a covering of angelic glory by this example of angelic excellence.